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  1. audioguru2

    Mosfet driver not outputing properly

    I'm joking. My wifey and I frequently go to the walkway there to walk our dog. Some of the boats are huge and very expensive. ;D
  2. audioguru2

    Mosfet driver not outputing properly

    I live here somewhere:
  3. audioguru2

    I need a datasheet for this car speaker

    JVC.com has no info about the speaker, so maybe it is counterfeight. Google has a link to E-Bay in France where a pair are being sold, but the newer 02A version. It is a mid-woofer that is only 6.5 inches with a fairly small magnet. It has a narrow rubber surround which indicates not far throw...
  4. audioguru2

    Mosfet driver not outputing properly

    EEK! A fuzzy Jpg. Please attach schematics as clear GIF or PNG file types. The Vb pins are dynamic and opposite each other. Download this pic to be clearer. This way should work:
  5. audioguru2

    What's a snubber capacitor, and what's it used for?

    A snubber capacitor is used so that a fast-rising voltage doesn't cause the thyristor to turn-on. A thyristor has a dv/dt rate-of-voltage-rise rating that it can withstand without turning on. A snubber capacitor slows-down the voltage rate-of-voltage-rise.
  6. audioguru2

    Antenna and TV standard

    My cable TV wire carries hundreds of analog ordinary TV channels' video and audio carrier frequencies, hundreds of digital TV channels including many that are thousands of miles away that I use for time-shifting, about 40 high-definition channels, about 60 pay-per-view channels including a...
  7. audioguru2

    speaker to line level

    SoundShark wants to amplify a "headunit" car radio. They have only 14W per channel, bridged into 4 ohms. Therefore each speaker wire has a max of only 3.7V AC on it which dissipates next to nothing (1.4mW) in the 10k attenuating resistor and much less in the series 1k pot. Any little pot will be...
  8. audioguru2

    100W Audio Amplfier By Smart Kit

    You need a substitution guide book. Go to the website of a transistor manufacturer whose transistors are available in your area. Maybe they have a substitution list.
  9. audioguru2

    Fridge door alarm circuit

    Hi Ivan, Welcome to out forum. ;D Are the diodes installed backwards? Are the pins of the transistor wired properly?
  10. audioguru2

    its been kind of .....DEAD lately...

    I don't use tubes anymore 'cause I can't buy 90V batteries anymore. When I was young I potted two 45V batteries and some neon bulbs in clear plastic as a chaser. After about a year IT BLEW UP! I didn't know that batteries need to be vented. Of course I drank Cuban Rum and Coke! But the...
  11. audioguru2

    0-24V 4A bench supply

    Pin 7 drives R11 and pin 8 drives R10. Maybe those resistors have a value much less than 10 thousand ohms.
  12. audioguru2

    0-24V 4A bench supply

    Then its pin 4 doesn't have a supply voltage connected. Pin 7 should go high when there is 10mV or less difference in voltage at its inputs due to its input offset voltage, then amplifies it a few hundred-thousand times. Pin 8 needs a little more voltage difference due to the hysteresis provided...
  13. audioguru2

    0-24V 4A bench supply

    Hi Smokey, Pin 7 should go high when the voltage at the slider of R22 that is caused by output current, exceeds the voltage at the slider of R20 its reference voltage. Pin 8 should go high when the voltage at pin 9 drops a little lower when the thermistor is hot, than the voltage at the slider...
  14. audioguru2

    100W Audio Amplfier By Smart Kit

    You don't need to know the value of the inductor, just make it like it says. I never had to substitute anything since in Canada I can buy anything I want. Maybe another member has a transistor substitution guide and can help you.
  15. audioguru2

    The Triac doesn't turn off when I connect it to DC voltage!

    Hi Shahriar, Study how a triac works in our Articles section. A triac is used with AC current and turns-off each hlaf-cycle when the AC passes through zero volts causing its current to drop to zero. The only way to turn it off is to cut its power or short it. Its gate won't turn it off. An SCR...
  16. audioguru2

    TTL pulse for counter

    Also add a 0.1uF ceramic and a 10uF electrolytic supply bypass capacitors to the circuit. ;D
  17. audioguru2

    speaker to line level

    Hi SoundShark, Welcome to our forum. ;D Instead of taking apart your headunit to try to find its preamp, you can attenuate the speaker output wirh a couple of resistors. The speaker output is only 3.5V to 4V at full output, so a 10k resistor connected to the live speaker wire (both might be...
  18. audioguru2

    its been kind of .....DEAD lately...

    The same snow storm that was in Chicago came here to Toronto. I threatened the Mayor that I will melt all the snow that they dump into my driveway and leave the street covered in ice. The Mayor replied that then my neighbours and I won't be going anywhere. It's too bad that snow is white and...
  19. audioguru2

    LM324, LM358 crossover distortion

    Hi Walid, Most opamps and audio amplifiers avoid crossover distortion in their complimentary NPN-PNP output stage by using class-AB with a couple of diodes in series between their bases to provide enough voltage for them to have idle current, for a smooth transistion from one transistor to the...
  20. audioguru2

    Question about Ground Loops

    When you connect together two grounded pieces of equipment with a shielded cable then you usually have a ground loop due to leakage current in the shield. Some people cutoff the electrical ground pin which is dangerous of an amplifier or oscilloscope to eliminate the ground loop. I disconnect...
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